Hydraulic starting system for engines



May 19, 1959 A. c. JENNY HYDRAULIC STARTLNG SYSTEM FOR ENGINES Filed May18, 1954 ai?. M m

JENNY YAY/1Min..

INVENTOR ALBERT C ATTORNEY United States Patent @hice 2,886,947 PatentedMay 19, 1959 HYDRAULIC STARTEN@ SYSTEM FOR ENGINES Albert (2. Jenny,Cleveland, Ohio, assigner, by direct and mesne assignments, to AmericanBosch Arma Corporation, Hempstead, NX., a corporation of New vtZerkApplication May 13, 1954, Serial No. 430,623

1 Claim. (Cl. 643-51) This invention relates to starting systems forinternal combustion engines, and more particularly to an hydraulicsystem including a fluid pressure accumulator.

One of the primary objects of the invention is to provide an improvedengine starting hydraulic system which includes an hydraulic enginestarting motor, `and wherein hydraulic pressure energy for operating thestarting motor is stored in an accumulator by an hydraulic hand pump forthe initial start and for supplying motor operating uid under pressurein the event of failure or exhaustion of the pressure iluid accumulatoror failure of an engine driven hydraulic pump which is used to rechargethe accumulator to the desired pressure.

Another object is to provide in such a system an unloading value sodesigned and incorporated in the hydraulic circuit that after the systemis charged to the desired operating pressure, the unloading valve willrelieve the engine driven pump load so that it will circulate hydraulicuid through the system at a relatively low pressure and automaticallycut in to recharge the accumulator to the regulated pressure when thestored fluid pressure drops to a predetermined degree.

Another object is to provide means in the form of an hydraulic fluidmetering Valve located between the accumulator and the motor that willbe responsive to hydraulic :Huid ow so as to limit the flow for eachcranking cycle and prevent exhausting the accumulator in the event theengine fails to start.

With the foregoing and other objects in view, the invention resides inthe combination of parts set forth in the following description andappended claim, certain embodiments thereof being illustrated in theaccompanying drawing, wherein the single gure is a diagrammaticillustration of an hydraulic engine starting system illustrative of theinvention, certain parts being broken away and shown in cross section tobetter illustrate the construction thereof.

Referring more particularly to the drawing, the system comprises, ingeneral, a fluid tank or reservoir 10, a hand pump 11, a piston typeaccumulator 12, au engine driven pump 13, an hydr-aulic starting motor14, an unloading valve and a ow metering valve 16.

The accumulator is preferably a piston type hydropneumatic accumulatorwhere iluid energy is stored under `pressure for actuating the startingmotor 14. As shown,

it comprises a cylinder 17 and a piston 18, slidably mounted therein. Acharge of gas under pressure is introduced by conventional means throughthe right end 19 of the cylinder into chamber Ztl behind the piston 18.Rigid with cylinder 17 is a cylinder head 21 to form an hydraulic iluidchamber 22 and an inlet condut 23` thereto from a conduit 24 from thedischarge side of the hand pump 11. I preferably employ a manual valve23 in conduit 23 adjacent the accumulator. When the valve 23 is opened,the accumulator may be charged byhand -pump 11, when I desire to breakthe engine, or turn it over slowly. In the closed position of valve 23',the

pressure fluid pumped by -the hand pump 11. is then conveyed throughpipes 24, 31, 32 and 33 into the motor 14 and,rwhen the pinion gear 36has been rstmeshed with `engine ring gear 37, and the valve 51 opened toopen passage from port 50 to 52, this hand pumped hydraulic pressureturns the engine over.

The hand pump 11 is a manually operated double acting pump for buildingup pressure in chamber 22 of the accumulator in front of the piston andmay comprise a suitable pivoted hand lever and plunger 26 actuatedthereby for forcing hydraulic iluid under pressure past a check valve`27 through conduit 24 into the accumulator. In this pumping operation,hydraulic iluid is pumped from the reservoir 10 through suction line 2Sand inlet conduit 29 into the hand pump casing.

The cranking motor 14 includes a housing 30 to receive inlet hydraulicpressure fluid from the accumulator through conduits 31, 32, meteringvalve 16 and conduit 33 which, after performing its function, isdischarged out through conduit 34 back into the reservoir 10. Thestarting, or cranking, motor is preferably an` .axial piston, rotatingcylinder drive, wobble plate duid motor with a drive assembly actuatedby a fluid pressure charge from the accumulator through the hand valvewhen opened. Briey, the starter drive shaft 35 is rotatably mounted inhousing 30 and carries a cranking pinion 36 that is automaticallyextended to the right into mesh with an engine tiywheel `ring gear 37carried by the engine crankshaft and spring returned after starting ofthe engine. A cylinder 38 is rotatably mounted in the housing 30 and issplined at 39 to shaft 35 to drive the latter. The cylinder is providedat its inner end with a plurality of bores 41%, each to receive anaxially slidable piston 41 provided at its outer end with a sphericalhead that bears against an axially inclined wobble plate 42. The innerends of the cylinder bores, in the rotation of the cylinder, alternatelyregister with inlet and outlet bores of a porting plate, to which themotor inlet and outlet conduits 33 and 34 are connected. Pressure fluidcauses reciprocation ofthe pistons, due to the angle of disposition ofthe wobble plate and this, in turn, rotates the cylinder, andconsequently the cranking shaft and pinion for the engine crankingoperation.

The engine driven pump 13 may bel of any suitable type to include -anengine driven pump shaft 43 carrying suitable gears 44 to draw hydraulictluid from the reservoir 10 through the suction line 28 through the pumpinlet 4S and out through the outlet 46 from which the hydraulic uid Howsthrough conduit 47 past a high pressure filter through the unloadingvalve assembly 15 and out through the conduit 31 into the accumulator12.

In the operation of the device, the hydraulic energy for cranking theengine is stored in the accumulator by means of the hydraulic hand pumpfor the initial start. This hydraulic iluid energy is stored in chamber22 in the cylinder ahead ofthe piston 18 against the expansive force olthe gas in chamber 20 behind the piston.

In'this system, the extension of the starter pinion for the admission of`hydraulic pressure iluid is accomplished by a single hand lever 49. Inthe drawing, the hand lever is shown to be in a position to retract thestarter pinion 36 out of engagement with the engine ring gear 37.Whilehydraulic fluid is free to enter the intake port 50 into the motorhousing from conduit 33, the plunger valve 51 remains closed to preventflow through the outlet port 52 to the porting plate 53 and the chambers40 back of the pistons 41 in the cylinder 38 for operating the motor. Inorder to start the motor, the hand crank 49 isr moved counter-clockwiseabout its pivot 54. This forces the starter pinion 36 into mesh with theengine flywheel ring gear 37. At the same time, it moves the plungervalve 51 to the left to establish communication between the inlet 50which is closed by a ball as shown and the outlet 52. The plunger valveis formed with grooves 55 to permit a finely metered ow from inlet 50 tooutlet 52 to initiate a'slow rotation of pinion 36 near its iinal stageof extension to insure proper mesh with ring gear 37. ln this manner,the hydraulic energy stored up in the accumulator rotates the crankingmotor `for starting of the engine.

I have found it yadvisable to provide some precautionary means againstthe continued oW of hydraulic pressure iluid from the accumulator to thestarting motor after a predetermined number of revolutions of thestarting pinion during a given cranking cycle. This is in order to avoidthe dissipation of all of the stored energy in the accumulator for asingle cranking cycle when, for some mechanical or electrical reason,the engine fails to start. One means of accomplishing this is anhydraulic metering fuse valve assembly generally indicated at 16 whichm-ay be of the type shown in Patent 2,592,486. The purpose of this valve16 is to provide some means that is strictly responsive to fluid owvolume rather than to uid pressure. It may comprise a sleeve 56 normallyurged to open position by a spring 59. Thus, upon operation of the handlever 49 to extend the starter piston and to open communication betweenthe inlet 50 and the outlet 52 to the porting plate of the motor, theoperating parts of the metering valve 16 are open to permit flow fromthe accumulator to the conduit 33 and then through the starting motor.Upon the completion of a pre-determined volume of iiow of such hydraulicfluid from the accumulator, the ball closing inlet 50 and sleeve areforced to the right against the action of their respective springs todiscontinue such flow.

As stated before, the accumulator is initially charged by the hydraulichand pump. After the engine has been started, it drives the engine pump13 in order to re-charge the accumulator and keep it charged to thedesired pressure. After the system has been charged by the engine pumpto the desired operating pressure, the unloading valve 15 in the circuitrelieves the engine pump work load in order to circulate the hydraulicuid through the system from the reservoir through the suction line 28out through conduit 47 and past the unloading valve casing throughconduit 63 and conduit 61 back into the reservoir 10. A movable valveelement of the unloading valve itself is indicated at 62 as being urgedto the right in response to a pre-determined pressure vin chamber 22 inthe accumul-ator ahead of the piston 18 conveyed through conduit 31.With this element 62 of the unloading valve being closed, the ow fromthe engine pump through conduit 47 does not enter conduit 31, but isbypassed through port 69 opening sensing valve 70 to permit pressurefluid to go through passage 71 to unseat bypass valve 72. The uid bypassvalve 72 when opened by the sensing valve 70 is directed through line 63and conduit 61 to the reservoir 10. If desired, a drain pipe 60 may beprovided from the by-pass line 61 back into the loading valve housing 15behind the sensing valve 70. The purpose of the unloading valve is thatof a pressure regulator to convert pressure from the engine driven pumpover to a low circulating pressure after the Iaccumulator has reachedthe desired maximum setting. When the stored fluid pressure in theaccumulator drops to a predetermined degree,

the unloading valve automatically cuts in and permits the engine drivenpump to re-charge the accumulator to the regulated pressure so that itcan be recharged to any desired maximum setting.

It will thus be seen that I have provided an hydraulic cranking systemfor cranking an engine where the energy is stored in an accumulator bymeans of an hydraulic hand pump for the initial start. After the engineis started, the engine driven hydraulic pump re-charges the accumulatorto the desired operating pressure. After the system is charged to thedesired operating pressure, the unloading valve in the circuit relievesthe engine pump work load so that it will circulate` hydraulic fluidthrough the system at a low pressure. When the stored fluid in theaccumulator drops to a pre-determined degree, the unloading valveautomatically cuts in and re-charges the accumulator to the regulatedpressure. Means have also been provided in the form of the meteringvalve assembly 16 to prevent the dissipation of all of the stored energyin the accumulator for a single cranking cycle in the event that theengine does not start after a pre-determined number of revolutions ofthe starter pinion.

The operation of the valve 16 is dependent upon operation of the handvalve 49 which will open the line 33, behind the valve 16. Fluidpressure from the line 32 will act on the internal telescopic sleeve 56to move this sleeve like a piston to the right as viewed in the drawingagainst the action of spring 57 and spring 59, thereby permitting apredetermined volume of fluid to pass the valve to operate the motor 14.

After anumber of revolutions of the motor, as determined by the volumeof the fluid, flow is cut 0E by the seating of the ball 50 in the valve16 against the seat 64 in valve 16. This condition will remain until thehandle 49 is moved to the inoperative position, thereby blocking off theflow from line 33 to the motor 14.

The valve 16 is further provided with a chamber 65 fed through passages66a to ducts 66. The valve chamber is connected by a minute passagewaynot shown to a second chamber 67 which bleeds a certain amount of thepressure iluid from chamber 65 to chamber 67 from whence it is led bypassages 68 to the underside of the ball 50 and the sleeve 56. At thispoint, with the handle 49 jn the closed position and the bleed tluidbuilding up in pressure behind the ball, the combination of suchincreasing tluid pressure and the springs 57 and 59 will force the ball50 from the seat 64 to thereby permit a further operation of the systemwhen the handle 49 is again moved to the operative position.

The hand pump is, of course, always available for storing energy in theaccumulator at any time, should the energy stored by the engine drivenpump be insutlicient for starting purposes. Moreover, by the provisionof manual valve 23', l may open it to charge the accumulator by the handpump or the engine driven pump. I may also close valve 23 and crank theengine slowly by the hand pump.

I claim:

An hydraulic engine starting system comprising an hydraulic startingmotor, an hydraulic reservoir, a pneumatic-hydraulic accumulator forstoring uid under pressure, a normally closed hand operable valvemounted on the starting motor, a conduit connecting said accumulator tosaid valve to deliver pressure uid thereto, said valve when openeddelivering said pressure fluid to the starting motor to operate thesame, a conduit leading from the discharge side of the starting motor tothe reservoir, a hand pump, conduit means connecting said hand pump tothe accumulator and to the conduit between the accumulator and thestarting motor, check valve means positioned in the conduit between thehand pump and accumulator to prevent reverse flow from the accumulatoror from the conduit between the accumulator and the starting motor backto said hand pump, conduit means connecting said hand pump with thereservoir, an engine driven pump, a conduit connecting said enginedriven pump to the accumulator, an automatic pressure responsive valveconnected in the conduit between the accumulator and the hand operatedvalve for limiting the volume of uid directed to the starting motor oneach operation of the hand operated valve, said pressure responsivevalve acting thereby to preserve the pressure in the accumulator whilesupplying enough uid under pressure to operate the starting motoradequately for engine starting purposes, conduit means connecting saidengine driven pump with said reservoir, an automatic unloading valveconnected in Q J the conduit between the engine driven pump and the accumulator, and conduit means connecting said unloading valve with thereservoir, said unloading valve being operative through its connectionwith the reservoir to bypass fluid from said engine driven pump at apreselected pressure level of the system to prevent to great a build upof pressure on the system by the engine driven pump, and said unloadingvalve including a check valve to pre vent return flow of fluid from theaccumulator to the engine driven pump.

2,043,453 Vickers June 9, 1936 6 Hill et al. Dec. 2, 1941 Clyde et alAug. 10, 1948 Wilson Apr. 12, 1949 Molyneux et al Feb. 28, 1950 SanfordMay 30, 1950 Stark Apr. S, 1952 Grier Feb. 17, 1953 Wishart June 16,1953 Jenny J'une 14, 1955 Jenny June 28, 1955 Hogeman Aug. 13, 1957

